Groundbreaking survey reveals the harsh truth about the decline of this hardy tree and the mountain wildlife that depends on it.

More About Whitebark Pine

Across the American West, whitebark pine trees are being wiped out by outbreaks of mountain pine beetles, which are encouraged by global warming. The whitebark pine is a crucial species in high-altitude environments, providing food and shelter for animals where few other trees can survive. While some pictures and expert observations had suggested an alarming decline of whitebark pine in the Yellowstone area – once a stronghold of whitebark pine in the United States – the full picture of its mortality in any portion of the tree’s range was not known.

NRDC has been at the forefront of research examining the full extent of this infestation, placing special focus on Greater Yellowstone, helping to quantify the impacts and take action before it is too late.

In 2008 and 2009, NRDC collaborated with the U.S. Forest Service to fund a groundbreaking study surveying the status of whitebark pine mortality throughout the entire 20-million-acre Greater Yellowstone Ecosystem (GYE). Using innovative aerial survey techniques designed for this project, the study was conceived and executed by a team of beetle and whitebark experts, geographers, and a skilled pilot, with the help of interns and volunteers. The researchers conducted survey flights over the entire ecosystem, using GPS-tagged photographs and a unique landscape-scale mortality classification system to document the health of whitebark pine. Nearly 5,000 aerial photos were collected across the ecosystem’s 14 mountain ranges, allowing the researchers to compile highly detailed maps of the condition of these high-altitude forests.

These new data paint a much more dire picture than previous estimates. First and foremost, more than half (51 percent) of all whitebark pine forests in the GYE showed high mortality caused by mountain pine beetles, and another 31 percent showed medium mortality. This means that just 18 percent of the whitebark in the ecosystem can be considered healthy, showing low or no beetle-caused mortality. Based on these data, and considering the rapid changes, leading experts predict that whitebark pine will be functionally extinct in the ecosystem—failing to provide food, shelter and hydrological functions—within the next 5 to 7 years. While some extreme high-altitude areas will see less whitebark mortality in the coming years, many slightly warmer areas have already experienced extensive mortality.

Deaths from mountain pine beetle attacks are also increasing rapidly in other areas of the tree’s range, from the U.S. Pacific Northwest to Canada’s Rocky Mountains and coastal ranges. In Washington and Oregon, where a higher percentage of whitebark pines have already been weakened by blister rust, whitebark mortality from beetles has skyrocketed in the past 5 years. In Canada, both coastal and interior mountain ranges have seen unprecedented mountain pine beetle outbreaks, which, as in the GYE, threaten entire landscapes.

...leading experts predict that whitebark pine will be functionally extinct in the ecosystem—failing to provide food, shelter and hydrological functions—within the next 5 to 7 years.

Despite the dramatic decline, there is hope that these ecosystems can be saved. The U.S. Fish and Wildlife Service is considering listing whitebark pine as a threatened or endangered species. Endangered Species Act protections would trigger a coordinated recovery plan across state and federal agencies and could bring increased resources for research, conservation, and restoration efforts.

Continued monitoring and efforts to search for beetle-resistant whitebark pine trees will be critical. At the same time, adaptation programs and strong protections for grizzly bears must be part of a program to respond to the effects of declining whitebark in Greater Yellowstone. Ultimately, taking bold action to combat climate change can help stabilize the ecosystem and give us a chance to restore balance to these critical forests.